//
// Created by win10 on 24-12-13.
//
#include<stdio.h>
#include <stdlib.h>
#define MAXSIZE 50
typedef int ElemType;
typedef  struct
{
    ElemType  *R;
    int  length;
} SSTable;
int Search(SSTable *T,ElemType e);
int main() {
    int n;
    scanf("%d",&n);
    SSTable A;
    A.R = (ElemType *)malloc(n*sizeof(ElemType));
    A.length = n;
    for(int i=0;i<n;i++) {
        scanf("%d", &A.R[i]);
    }
    int m;
    scanf("%d",&m);
    int result=Search(&A,m);
    if(result!=-1) {
        printf("%d\n",result+1);
    }else {
        printf("NOT FOUND");
    }
    return 0;
}
int Search(SSTable *T,ElemType e) {
    int low=0,high=T->length-1,mid;
    while(low<=high) {
        mid=(low+high)/2;
        if(T->R[mid]==e) {
            return mid;
        }else if(T->R[mid]<e) {
            low=mid+1;
        }else{
            high=mid-1;
        }
    }
    return -1;
}